JP3059345B2 - One-way clutch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a one-way clutch in which a number of sprags are interposed between an outer race and an inner race, and the operation of the sprags transmits torque in one direction.

[0002]

2. Description of the Related Art FIG. 13 shows a conventional technique. In FIG. 13, reference numeral 1 denotes a rotary member such as a flywheel connected to a crankshaft of a motorcycle engine. A cylindrical outer race 2 is protruded rightward (right side) of the rotary member 1 and fixed by bolting. I do. The outer race 2 integrally has a mounting flange 2a projecting outward in the radial direction at the left end and a regulating flange 2b projecting radially inward at the right end. The outer flange 2 is fastened to the rotating member 1 by bolts 8 at the mounting flange 2a. Fix it. 3 is an inner race fixed to the boss of the starter gear,
The outer race 2 is coaxially fitted.

A large number of sprags 4 arranged at a predetermined pitch in the circumferential direction are interposed between the outer race 2 and the inner race 3 by a retainer 7. The retainer 7 is formed as follows by punching and drawing a sheet metal material using a press machine. That is, the rectangular holding hole 7 is provided in the cylindrical main body.
are formed at a predetermined pitch in the circumferential direction, and the outer peripheral end of the sprag 4 is fitted and held rotatably by each holding hole 7a. The retainer 7 has flanges 7b, 7c protruding radially outward at both left and right ends thereof, and each flange 7b, 7c faces the right surface of the rotating member 1 and the inner surface (left surface) of the regulating flange 2b of the outer race 2. Sprag 4 and retainer 7
Is prevented from moving left and right in the outer race 2.

Each of the sprags 4 has a groove 5 extending in the circumferential direction on the inner peripheral side thereof. A return spring 6 having a ring shape of a coil spring is fitted into the groove 5 so that each sprag 4 is engaged in the engagement direction. Energize the rotation.

[0005]

In the prior art described above, since the retainer 7 is loosely fitted in the outer race 2, the sprag 4 cannot follow the rotation of the outer race 2 slowly. When the directional clutch is turned off, the timing of disengaging the sprag 4 from the inner race 3 is delayed, and the contact surface between the sprag 4 and the inner race 3 is worn. Further, at the time of assembling, the holding force of the sprags 4 by the return spring 6 is weak, and at the time of assembling, the sprags 4 are inadvertently moved in the axial direction, making it difficult to assemble smoothly.

[0006]

Means for Solving the Problems The present invention is configured as follows to achieve the above object. That is, the annular outer race and the inner race are fitted coaxially, the inner end of the outer race is fixed to the side surface of the rotating member, and a number of sprags and a number of holding holes are formed between the outer race and the inner race in the circumferential direction. An annular retainer having a predetermined pitch is provided at a predetermined pitch, and sprags are fitted into the retaining holes of the retainer, and the sprags are arranged at a predetermined pitch in a circumferential direction. the pin-like projections in part, also a flange projecting radially outward to the inner end portion of the retainer are respectively formed, of the retainer to the first recess to form a first recess on the outer surface of each sprag the projections are fitted, the flange of the retainer is fitted in the notch so as to form a notch in the annular inner peripheral portion of the inner side of the outer race, the front inside wall Cross-section with a pressing portion for pressing an elastic piece for elastically pressed, and the engagement piece and retainer engaging the inner edge of the retaining hole in the outer wall on the outer side between the rotating member and the flange In this configuration, a U-shaped and annular retainer strap is provided. Also, a second recess is formed on the inner side surface of each sprag, and a projection that fits into the second recess is provided on the retainer strap.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a main part of a one-way clutch according to a first embodiment of the present invention. In FIG. 1, A is a one-way clutch in which a number of sprags 12 are interposed between an outer race 10 and an inner race 11, and each sprag 12 is held at a predetermined pitch in a circumferential direction by a retainer 17 made of a steel plate. . The outer race 10 has a mounting flange 10a protruding radially outward at a left end of a cylindrical main body, and an annular cutout 1 recessed radially outward at an inner peripheral portion at a left end.
The mounting flange 10a is fastened to the right side (side) of the rotating member 1 such as a flywheel connected to the crankshaft of the motorcycle engine by the bolt 8 at the mounting flange 10a. Reference numeral 11 denotes an inner race fixed to the boss of the starter gear, which is coaxially fitted into the outer race 10.

As shown in FIGS. 1, 5 and 6, each of the sprags 12 has a circumferentially extending groove 13 on its inner peripheral side.
And the first recess 1 is formed on the outer surface of each sprag 12.
4 is formed, and a return spring 16 having a ring shape of a coil spring is fitted into the groove 13 to urge each sprag 12 to rotate in the engagement direction. As shown in FIGS. 2 to 4, the retainer 17 is formed as follows by stamping and drawing a sheet metal material using a press machine. That is, rectangular holding holes 18 are formed in the cylindrical main body at a predetermined pitch in the circumferential direction, and pin-shaped projections 19 are formed on the outer edges of the holding holes 18. Further, flanges 20 and 21 projecting outward in the radial direction are formed at both left and right ends of the main body, and the left flange 20 is formed to have a larger diameter than the right flange 21.

The retainer 17 is, as shown in FIG.
The left flange 20 is fitted into the notch 10b of the outer race 10 to restrict the lateral movement in the outer race 10.
The sprag 12 has its outer peripheral portion fitted into the holding hole 18, the first concave portion 14 of the sprag 12 faces the projection 19 of the retainer 17, and the left flange 20.
, A retainer 17 is frictionally engaged with the outer race 10 by the retainer strap 25, and the sprags 12 are pressed and moved outward (to the right in FIG. 1) to retain the first recess 14. 17 is fitted to the projection 19.

As shown in FIGS. 7 to 9, the retainer strap 25 is formed as follows by cutting and bending a steel plate material having excellent spring properties. That is, the belt-shaped bottom wall 2
An inner wall 27 and an outer wall (pressing portion) 28 which stand upward on both sides in the width direction and face each other are formed at predetermined pitches in the longitudinal direction and in the same number as the holding holes 18 of the retainer 17. A tongue-shaped elastic piece 29 protruding inwardly from the inner side wall 27 is formed at the center in the longitudinal direction, and a hook-shaped engaging piece 30 that is turned inward and bent inward is formed at the upper end of the outer side wall 28. .

As shown by the phantom line in FIG. 1, the retainer strap 25 has its bottom wall 26 facing the inner periphery of the left portion of the retainer 17, and in this state, is pushed outward in the radial direction to press the inner wall 27 and the elastic piece 29. Along the left surface (outer surface) of the left flange 20 of the outer race 10, and the outer wall 28 between the inner edge of the holding hole 18 and the sprags 12, and the upper end of the outer wall 28, Piece 3
0 is engaged with the inner edge of the holding hole 18.

The retainer strap 25 is provided after the sprag 12 is fitted into the holding hole 18 of the retainer 17 and the sprag 12 and the retainer 17 are interposed between the outer race 10 and the inner race 11. First, it is attached to the retainer 17 as described above. Thus, the sprags 12 are moved outward (to the right in FIG. 1) in the holding holes 18 of the retainers 17 by the outer walls (pressing portions) 28 of the retainer straps 25 to move the first recesses 14 to the projections 19 of the retainers 17. The sprags 12 and the retainer 17 and the return spring 16 are unitized and interposed between the outer race 10 and the inner race 11 as shown in FIG. Inner wall 27 of retainer strap 25
The elastic piece 29 is accommodated in the notch 10b of the outer race 10.

FIG. 10 shows a second embodiment. This one is
A hemispherical second concave portion 15 facing the first concave portion 14 is formed on the inner side surface (left side surface) of each of the sprags 12 described above, and the protrusion 31 fitted to the second concave portion 15 is formed on the outer wall 28 of the retainer strap 25. Is provided. This projection 31 is provided on each outer wall 28.
The central portion in the longitudinal direction is divided by a slit, and the divided pieces are projected outward and the projections are curved in an arc shape so that the outer wall 28 can be elastically deformed inward and outward. Others are the same as those of the first embodiment.

In the second embodiment, first, the retainer strap 25 is attached to the left side of the retainer 17, and then, as shown in FIG.
As shown by the phantom line, the first concave portion 14 of the sprag 12 is fitted into the projection 19 of the retainer 17, and in this state, the sprag 12 is rotated about the projection 19 in the direction of the arrow (A) to On the left side of the retainer strap 25
After the protrusion 31 is elastically deformed to the left, the protrusion 31 is elastically restored and fitted into the second concave portion 15 of the sprag 12, whereby each sprag 12, the retainer 17 and the return spring 16 are unitized.

FIG. 11 shows a third embodiment. This one is
A vertically elongated second concave portion 15a is formed on the inner side surface (left side surface) of each sprag 12 so as to face the first concave portion 14, and a retainer strap 25 is provided with a protrusion 31a that can be fitted into the second concave portion 15a. The projection 31a is provided on each outer wall 28.
11 is cut by a slit extending from the center in the longitudinal direction toward the bottom wall 26, and the divided pieces are bent in the direction of arrow (a) from below as shown by the imaginary line in FIG. 15a, each sprag 12 and retainer 17 and return spring 1
6 is unitized. Others are the same as those of the first embodiment.

FIG. 12 shows a fourth embodiment. This one is
The inner side surface (left side surface) of each sprag 12 is smoothed, and the retainer strap 25 is provided with a projection 31 b that can be brought into contact with the inner side surface of the sprag 12. This projection 31b is formed on each outer wall 2
8 is divided by a slit extending from the center in the longitudinal direction toward the bottom wall 26, and the divided pieces are bent in the direction of arrow (c) from below as shown by the imaginary line in FIG. , The projection 31b and the outer wall 28 contact the inner surface of the sprag 12 with a wide area, and each sprag 12, the retainer 17 and the return spring 16 are unitized. Others are the same as those of the first embodiment.

According to the above embodiment, the retainer 17 has the left (inside) flange 20 formed by the notch 10 b of the outer race 10 due to the reaction force of the elastic piece 29 of the retainer strap 25.
Of the outer race 10 and the rotating member 1
, And each sprag 12 rotates well following the rotation of the outer race 10. Therefore, the sprags 12 are quickly separated from the inner race 11 after the engine is started, that is, when the one-way clutch is turned off, and the contact surface between the sprags 12 and the inner race 11 is less likely to be worn.

Each sprag 12 fitted into the holding hole 18 of the retainer 17 is pushed outward by the outer wall 28 of the retainer strap 25 so that the first recess 14 is fitted into the projection 19 of the retainer 17. Each sprag 12 is a retainer 1
7 will not accidentally leave. In particular, in the second and third embodiments, the protrusion 19 provided on the retainer 17 and the protrusion 31 (31a) provided on the retainer strap 25 are formed by the first recess 14 and the second recess 15 formed on both sides of the sprag 12.
(15a), and each sprag 12 is more stably held by the retainer 17. Therefore, each sprag 12, the retainer 17, and the return spring 16 can be unitized and interposed between the outer race 10 and the inner race 11, and the sprag 12 can be assembled between the outer race 10 and the inner race 11. Can be easily performed.

[0019]

As is apparent from the above description, according to the present invention, since the retainer frictionally engages with the outer race and each sprag rotates satisfactorily following the rotation of the outer race 10, the one-way clutch is turned off. At this time, the sprags are quickly separated from the inner race, and the contact surface between the sprags and the inner race is less likely to be worn. In addition, since the sprags, retainers and return springs of small items can be unitized and interposed between the outer race and the inner race, the sprags can be easily assembled between the outer race and the inner race. Has the effect of

[Brief description of the drawings]

FIG. 1 is a sectional side view of a main part of a one-way clutch showing a first embodiment of the present invention.

FIG. 2 is a partial cross-sectional side view of a retainer according to the present invention.

FIG. 3 is a sectional view taken along the line III-III of FIG. 2;

FIG. 4 is a plan view of FIG. 3;

FIG. 5 is a side view of a sprag according to the present invention.

FIG. 6 is a sectional view taken along the line VI-VI of FIG. 5;

FIG. 7 is a partial side view of a retainer strap according to the present invention.

FIG. 8 is a sectional view taken along the line VIII-VIII in FIG. 7;

FIG. 9 is a plan view of FIG.

FIG. 10 is a cross-sectional side view of a main part of a sprag engaging portion according to a second embodiment of the present invention.

FIG. 11 is a cross-sectional side view of a main part of a sprag engaging portion according to a third embodiment of the present invention.

FIG. 12 is a cross-sectional side view of a main part of a sprag locking portion according to a fourth embodiment of the present invention.

FIG. 13 is a sectional side view of a main part of a one-way clutch showing a conventional example.

[Explanation of symbols]

 A One-way clutch 1 Rotating member 8 Bolt 10 Outer race 10a Mounting flange 10b Notch 11 Inner race 12 Sprag 13 Groove 14 First concave 15, 15a Second concave 16 Return spring 17 Retainer 18 Retaining hole 19 Projection 20, 21, Flange 25 Retainer strap 26 Bottom wall 27 Inner side wall 28 Outer side wall (pressing portion) 29 Elastic piece 30 Engagement piece 31, 31a, 31b Projection

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F16D 41/00-41/36

Claims (2)

(57) [Claims] An annular outer race and an inner race are coaxially fitted with each other, an inner end of the outer race is fixed to a side surface of a rotating member, and a number of sprags and a number of holding holes are provided between the outer race and the inner race. An annular retainer having a predetermined pitch in the circumferential direction and a sprag fitted into the retaining hole of the retainer to arrange the sprags at a predetermined pitch in the circumferential direction. A pin-shaped projection is formed on the outer edge of the sprag, and a flange protruding radially outward is formed on the inner end of the retainer.
Forming a recess, fitting the protrusion of the retainer into the first recess, forming an annular notch in the inner peripheral portion of the inner side of the outer race , fitting the flange of the retainer into the notch, and a pressing portion for pressing an elastic piece for elastically pressed into between the rotating member and the flange, and the engaging piece and the retainer engaging the inner edge of the retaining hole in the outer wall outwardly A one-way clutch provided with a retainer strap having a U-shaped cross section and an annular shape. 2. The one-way clutch according to claim 1, wherein a second concave portion is formed on an inner surface of each of said sprags, and a projection is provided on said retainer strap so as to fit into said second concave portion.